Lower Respiratory (confined to thoracic cavity)

Question 1

Bronchial anatomy

Answer 1

1. primary bronchi (2)
2. secondary or lobar bronchi (5)
3. tertiary bronchi
   - ciliated columnar epithelium; few cartilage discs surrounded by smooth muscle
4. terminal bronchioles:
   - simple cuboidal epithelium; cartilage replaced by smooth muscle
5. respiratory bronchioles ( .4mm diameter):
   - simple cuboidal epithelium
   - no cilia or goblet cells
6. alveoli ( .25 mm diameter):
   - simple squamous epithelium only
   - surrounded by a capillary network for exchange of gases and nutrients.

Question 2

pulmonary anatomy

Answer 2

-Lungs protected and lubricated by pleurae

Question 3

Breathing mechanics

Answer 3

1. Inspiration:
   - contraction (lowering) of the diaphragm
   - thoracic expansion–> lowered intrathoracic pressure–> atmospheric air drawn in via airways
   - synergistic muscles: external intercostals and sternocleidomastoids
2. Expiration:
   - relaxation (raising) of the diaphragm
   - thoracic shrinkage–> intrathoracic pressure raised–> air forced out through upper airways
   - synergistic muscles: internal intercostals and abdominal group

Question 4

impairment of alveolar function

Answer 4

1. Pneumonia: fluid and WBC infiltration into alveoli
2. Emphysema: consolidation of alveoli + lost elasticity
3. Tuberculosis: bacterial infection causing fibrosis of lung tissue
4. Respiratory distress syndrome: collapse of alveoli at birth due to low surfactant

Question 5

impairment of other respiratory structures

Answer 5

1. Asthma: allergic constriction of the bronchioles
2. pleuritis (pleurisy): inflammation of the pluera
3. Pneumothorax: airway into the chest cavity

Question 6

impairment of pulmonary circulation

Answer 6

1. pulmonary edema (swelling): fluid accumulation in alveoli due to weak left ventricle and high pulmonary blood pressure. (congestive heart failure)